forked from torvalds/linux
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathsunzilog.c
1774 lines (1467 loc) · 44 KB
/
sunzilog.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
* sunzilog.c
*
* Driver for Zilog serial chips found on Sun workstations and
* servers. This driver could actually be made more generic.
*
* This is based on the old drivers/sbus/char/zs.c code. A lot
* of code has been simply moved over directly from there but
* much has been rewritten. Credits therefore go out to Eddie
* C. Dost, Pete Zaitcev, Ted Ts'o and Alex Buell for their
* work there.
*
* Copyright (C) 2002 David S. Miller (davem@redhat.com)
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/circ_buf.h>
#include <linux/serial.h>
#include <linux/sysrq.h>
#include <linux/console.h>
#include <linux/spinlock.h>
#ifdef CONFIG_SERIO
#include <linux/serio.h>
#endif
#include <linux/init.h>
#include <asm/io.h>
#include <asm/irq.h>
#ifdef CONFIG_SPARC64
#include <asm/fhc.h>
#endif
#include <asm/sbus.h>
#if defined(CONFIG_SERIAL_SUNZILOG_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#include <linux/serial_core.h>
#include "suncore.h"
#include "sunzilog.h"
/* On 32-bit sparcs we need to delay after register accesses
* to accommodate sun4 systems, but we do not need to flush writes.
* On 64-bit sparc we only need to flush single writes to ensure
* completion.
*/
#ifndef CONFIG_SPARC64
#define ZSDELAY() udelay(5)
#define ZSDELAY_LONG() udelay(20)
#define ZS_WSYNC(channel) do { } while (0)
#else
#define ZSDELAY()
#define ZSDELAY_LONG()
#define ZS_WSYNC(__channel) \
sbus_readb(&((__channel)->control))
#endif
static int num_sunzilog;
#define NUM_SUNZILOG num_sunzilog
#define NUM_CHANNELS (NUM_SUNZILOG * 2)
#define KEYBOARD_LINE 0x2
#define MOUSE_LINE 0x3
#define ZS_CLOCK 4915200 /* Zilog input clock rate. */
#define ZS_CLOCK_DIVISOR 16 /* Divisor this driver uses. */
/*
* We wrap our port structure around the generic uart_port.
*/
struct uart_sunzilog_port {
struct uart_port port;
/* IRQ servicing chain. */
struct uart_sunzilog_port *next;
/* Current values of Zilog write registers. */
unsigned char curregs[NUM_ZSREGS];
unsigned int flags;
#define SUNZILOG_FLAG_CONS_KEYB 0x00000001
#define SUNZILOG_FLAG_CONS_MOUSE 0x00000002
#define SUNZILOG_FLAG_IS_CONS 0x00000004
#define SUNZILOG_FLAG_IS_KGDB 0x00000008
#define SUNZILOG_FLAG_MODEM_STATUS 0x00000010
#define SUNZILOG_FLAG_IS_CHANNEL_A 0x00000020
#define SUNZILOG_FLAG_REGS_HELD 0x00000040
#define SUNZILOG_FLAG_TX_STOPPED 0x00000080
#define SUNZILOG_FLAG_TX_ACTIVE 0x00000100
unsigned int cflag;
unsigned char parity_mask;
unsigned char prev_status;
#ifdef CONFIG_SERIO
struct serio *serio;
int serio_open;
#endif
};
#define ZILOG_CHANNEL_FROM_PORT(PORT) ((struct zilog_channel __iomem *)((PORT)->membase))
#define UART_ZILOG(PORT) ((struct uart_sunzilog_port *)(PORT))
#define ZS_IS_KEYB(UP) ((UP)->flags & SUNZILOG_FLAG_CONS_KEYB)
#define ZS_IS_MOUSE(UP) ((UP)->flags & SUNZILOG_FLAG_CONS_MOUSE)
#define ZS_IS_CONS(UP) ((UP)->flags & SUNZILOG_FLAG_IS_CONS)
#define ZS_IS_KGDB(UP) ((UP)->flags & SUNZILOG_FLAG_IS_KGDB)
#define ZS_WANTS_MODEM_STATUS(UP) ((UP)->flags & SUNZILOG_FLAG_MODEM_STATUS)
#define ZS_IS_CHANNEL_A(UP) ((UP)->flags & SUNZILOG_FLAG_IS_CHANNEL_A)
#define ZS_REGS_HELD(UP) ((UP)->flags & SUNZILOG_FLAG_REGS_HELD)
#define ZS_TX_STOPPED(UP) ((UP)->flags & SUNZILOG_FLAG_TX_STOPPED)
#define ZS_TX_ACTIVE(UP) ((UP)->flags & SUNZILOG_FLAG_TX_ACTIVE)
/* Reading and writing Zilog8530 registers. The delays are to make this
* driver work on the Sun4 which needs a settling delay after each chip
* register access, other machines handle this in hardware via auxiliary
* flip-flops which implement the settle time we do in software.
*
* The port lock must be held and local IRQs must be disabled
* when {read,write}_zsreg is invoked.
*/
static unsigned char read_zsreg(struct zilog_channel __iomem *channel,
unsigned char reg)
{
unsigned char retval;
sbus_writeb(reg, &channel->control);
ZSDELAY();
retval = sbus_readb(&channel->control);
ZSDELAY();
return retval;
}
static void write_zsreg(struct zilog_channel __iomem *channel,
unsigned char reg, unsigned char value)
{
sbus_writeb(reg, &channel->control);
ZSDELAY();
sbus_writeb(value, &channel->control);
ZSDELAY();
}
static void sunzilog_clear_fifo(struct zilog_channel __iomem *channel)
{
int i;
for (i = 0; i < 32; i++) {
unsigned char regval;
regval = sbus_readb(&channel->control);
ZSDELAY();
if (regval & Rx_CH_AV)
break;
regval = read_zsreg(channel, R1);
sbus_readb(&channel->data);
ZSDELAY();
if (regval & (PAR_ERR | Rx_OVR | CRC_ERR)) {
sbus_writeb(ERR_RES, &channel->control);
ZSDELAY();
ZS_WSYNC(channel);
}
}
}
/* This function must only be called when the TX is not busy. The UART
* port lock must be held and local interrupts disabled.
*/
static void __load_zsregs(struct zilog_channel __iomem *channel, unsigned char *regs)
{
int i;
/* Let pending transmits finish. */
for (i = 0; i < 1000; i++) {
unsigned char stat = read_zsreg(channel, R1);
if (stat & ALL_SNT)
break;
udelay(100);
}
sbus_writeb(ERR_RES, &channel->control);
ZSDELAY();
ZS_WSYNC(channel);
sunzilog_clear_fifo(channel);
/* Disable all interrupts. */
write_zsreg(channel, R1,
regs[R1] & ~(RxINT_MASK | TxINT_ENAB | EXT_INT_ENAB));
/* Set parity, sync config, stop bits, and clock divisor. */
write_zsreg(channel, R4, regs[R4]);
/* Set misc. TX/RX control bits. */
write_zsreg(channel, R10, regs[R10]);
/* Set TX/RX controls sans the enable bits. */
write_zsreg(channel, R3, regs[R3] & ~RxENAB);
write_zsreg(channel, R5, regs[R5] & ~TxENAB);
/* Synchronous mode config. */
write_zsreg(channel, R6, regs[R6]);
write_zsreg(channel, R7, regs[R7]);
/* Don't mess with the interrupt vector (R2, unused by us) and
* master interrupt control (R9). We make sure this is setup
* properly at probe time then never touch it again.
*/
/* Disable baud generator. */
write_zsreg(channel, R14, regs[R14] & ~BRENAB);
/* Clock mode control. */
write_zsreg(channel, R11, regs[R11]);
/* Lower and upper byte of baud rate generator divisor. */
write_zsreg(channel, R12, regs[R12]);
write_zsreg(channel, R13, regs[R13]);
/* Now rewrite R14, with BRENAB (if set). */
write_zsreg(channel, R14, regs[R14]);
/* External status interrupt control. */
write_zsreg(channel, R15, regs[R15]);
/* Reset external status interrupts. */
write_zsreg(channel, R0, RES_EXT_INT);
write_zsreg(channel, R0, RES_EXT_INT);
/* Rewrite R3/R5, this time without enables masked. */
write_zsreg(channel, R3, regs[R3]);
write_zsreg(channel, R5, regs[R5]);
/* Rewrite R1, this time without IRQ enabled masked. */
write_zsreg(channel, R1, regs[R1]);
}
/* Reprogram the Zilog channel HW registers with the copies found in the
* software state struct. If the transmitter is busy, we defer this update
* until the next TX complete interrupt. Else, we do it right now.
*
* The UART port lock must be held and local interrupts disabled.
*/
static void sunzilog_maybe_update_regs(struct uart_sunzilog_port *up,
struct zilog_channel __iomem *channel)
{
if (!ZS_REGS_HELD(up)) {
if (ZS_TX_ACTIVE(up)) {
up->flags |= SUNZILOG_FLAG_REGS_HELD;
} else {
__load_zsregs(channel, up->curregs);
}
}
}
static void sunzilog_change_mouse_baud(struct uart_sunzilog_port *up)
{
unsigned int cur_cflag = up->cflag;
int brg, new_baud;
up->cflag &= ~CBAUD;
up->cflag |= suncore_mouse_baud_cflag_next(cur_cflag, &new_baud);
brg = BPS_TO_BRG(new_baud, ZS_CLOCK / ZS_CLOCK_DIVISOR);
up->curregs[R12] = (brg & 0xff);
up->curregs[R13] = (brg >> 8) & 0xff;
sunzilog_maybe_update_regs(up, ZILOG_CHANNEL_FROM_PORT(&up->port));
}
static void sunzilog_kbdms_receive_chars(struct uart_sunzilog_port *up,
unsigned char ch, int is_break,
struct pt_regs *regs)
{
if (ZS_IS_KEYB(up)) {
/* Stop-A is handled by drivers/char/keyboard.c now. */
#ifdef CONFIG_SERIO
if (up->serio_open)
serio_interrupt(up->serio, ch, 0, regs);
#endif
} else if (ZS_IS_MOUSE(up)) {
int ret = suncore_mouse_baud_detection(ch, is_break);
switch (ret) {
case 2:
sunzilog_change_mouse_baud(up);
/* fallthru */
case 1:
break;
case 0:
#ifdef CONFIG_SERIO
if (up->serio_open)
serio_interrupt(up->serio, ch, 0, regs);
#endif
break;
};
}
}
static struct tty_struct *
sunzilog_receive_chars(struct uart_sunzilog_port *up,
struct zilog_channel __iomem *channel,
struct pt_regs *regs)
{
struct tty_struct *tty;
unsigned char ch, r1;
tty = NULL;
if (up->port.info != NULL && /* Unopened serial console */
up->port.info->tty != NULL) /* Keyboard || mouse */
tty = up->port.info->tty;
for (;;) {
r1 = read_zsreg(channel, R1);
if (r1 & (PAR_ERR | Rx_OVR | CRC_ERR)) {
sbus_writeb(ERR_RES, &channel->control);
ZSDELAY();
ZS_WSYNC(channel);
}
ch = sbus_readb(&channel->control);
ZSDELAY();
/* This funny hack depends upon BRK_ABRT not interfering
* with the other bits we care about in R1.
*/
if (ch & BRK_ABRT)
r1 |= BRK_ABRT;
if (!(ch & Rx_CH_AV))
break;
ch = sbus_readb(&channel->data);
ZSDELAY();
ch &= up->parity_mask;
if (unlikely(ZS_IS_KEYB(up)) || unlikely(ZS_IS_MOUSE(up))) {
sunzilog_kbdms_receive_chars(up, ch, 0, regs);
continue;
}
if (tty == NULL) {
uart_handle_sysrq_char(&up->port, ch, regs);
continue;
}
if (unlikely(tty->flip.count >= TTY_FLIPBUF_SIZE)) {
tty->flip.work.func((void *)tty);
/*
* The 8250 bails out of the loop here,
* but we need to read everything, or die.
*/
if (tty->flip.count >= TTY_FLIPBUF_SIZE)
continue;
}
/* A real serial line, record the character and status. */
*tty->flip.char_buf_ptr = ch;
*tty->flip.flag_buf_ptr = TTY_NORMAL;
up->port.icount.rx++;
if (r1 & (BRK_ABRT | PAR_ERR | Rx_OVR | CRC_ERR)) {
if (r1 & BRK_ABRT) {
r1 &= ~(PAR_ERR | CRC_ERR);
up->port.icount.brk++;
if (uart_handle_break(&up->port))
continue;
}
else if (r1 & PAR_ERR)
up->port.icount.parity++;
else if (r1 & CRC_ERR)
up->port.icount.frame++;
if (r1 & Rx_OVR)
up->port.icount.overrun++;
r1 &= up->port.read_status_mask;
if (r1 & BRK_ABRT)
*tty->flip.flag_buf_ptr = TTY_BREAK;
else if (r1 & PAR_ERR)
*tty->flip.flag_buf_ptr = TTY_PARITY;
else if (r1 & CRC_ERR)
*tty->flip.flag_buf_ptr = TTY_FRAME;
}
if (uart_handle_sysrq_char(&up->port, ch, regs))
continue;
if (up->port.ignore_status_mask == 0xff ||
(r1 & up->port.ignore_status_mask) == 0) {
tty->flip.flag_buf_ptr++;
tty->flip.char_buf_ptr++;
tty->flip.count++;
}
if ((r1 & Rx_OVR) &&
tty->flip.count < TTY_FLIPBUF_SIZE) {
*tty->flip.flag_buf_ptr = TTY_OVERRUN;
tty->flip.flag_buf_ptr++;
tty->flip.char_buf_ptr++;
tty->flip.count++;
}
}
return tty;
}
static void sunzilog_status_handle(struct uart_sunzilog_port *up,
struct zilog_channel __iomem *channel,
struct pt_regs *regs)
{
unsigned char status;
status = sbus_readb(&channel->control);
ZSDELAY();
sbus_writeb(RES_EXT_INT, &channel->control);
ZSDELAY();
ZS_WSYNC(channel);
if (status & BRK_ABRT) {
if (ZS_IS_MOUSE(up))
sunzilog_kbdms_receive_chars(up, 0, 1, regs);
if (ZS_IS_CONS(up)) {
/* Wait for BREAK to deassert to avoid potentially
* confusing the PROM.
*/
while (1) {
status = sbus_readb(&channel->control);
ZSDELAY();
if (!(status & BRK_ABRT))
break;
}
sun_do_break();
return;
}
}
if (ZS_WANTS_MODEM_STATUS(up)) {
if (status & SYNC)
up->port.icount.dsr++;
/* The Zilog just gives us an interrupt when DCD/CTS/etc. change.
* But it does not tell us which bit has changed, we have to keep
* track of this ourselves.
*/
if ((status ^ up->prev_status) ^ DCD)
uart_handle_dcd_change(&up->port,
(status & DCD));
if ((status ^ up->prev_status) ^ CTS)
uart_handle_cts_change(&up->port,
(status & CTS));
wake_up_interruptible(&up->port.info->delta_msr_wait);
}
up->prev_status = status;
}
static void sunzilog_transmit_chars(struct uart_sunzilog_port *up,
struct zilog_channel __iomem *channel)
{
struct circ_buf *xmit;
if (ZS_IS_CONS(up)) {
unsigned char status = sbus_readb(&channel->control);
ZSDELAY();
/* TX still busy? Just wait for the next TX done interrupt.
*
* It can occur because of how we do serial console writes. It would
* be nice to transmit console writes just like we normally would for
* a TTY line. (ie. buffered and TX interrupt driven). That is not
* easy because console writes cannot sleep. One solution might be
* to poll on enough port->xmit space becomming free. -DaveM
*/
if (!(status & Tx_BUF_EMP))
return;
}
up->flags &= ~SUNZILOG_FLAG_TX_ACTIVE;
if (ZS_REGS_HELD(up)) {
__load_zsregs(channel, up->curregs);
up->flags &= ~SUNZILOG_FLAG_REGS_HELD;
}
if (ZS_TX_STOPPED(up)) {
up->flags &= ~SUNZILOG_FLAG_TX_STOPPED;
goto ack_tx_int;
}
if (up->port.x_char) {
up->flags |= SUNZILOG_FLAG_TX_ACTIVE;
sbus_writeb(up->port.x_char, &channel->data);
ZSDELAY();
ZS_WSYNC(channel);
up->port.icount.tx++;
up->port.x_char = 0;
return;
}
if (up->port.info == NULL)
goto ack_tx_int;
xmit = &up->port.info->xmit;
if (uart_circ_empty(xmit)) {
uart_write_wakeup(&up->port);
goto ack_tx_int;
}
if (uart_tx_stopped(&up->port))
goto ack_tx_int;
up->flags |= SUNZILOG_FLAG_TX_ACTIVE;
sbus_writeb(xmit->buf[xmit->tail], &channel->data);
ZSDELAY();
ZS_WSYNC(channel);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
up->port.icount.tx++;
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&up->port);
return;
ack_tx_int:
sbus_writeb(RES_Tx_P, &channel->control);
ZSDELAY();
ZS_WSYNC(channel);
}
static irqreturn_t sunzilog_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
struct uart_sunzilog_port *up = dev_id;
while (up) {
struct zilog_channel __iomem *channel
= ZILOG_CHANNEL_FROM_PORT(&up->port);
struct tty_struct *tty;
unsigned char r3;
spin_lock(&up->port.lock);
r3 = read_zsreg(channel, R3);
/* Channel A */
tty = NULL;
if (r3 & (CHAEXT | CHATxIP | CHARxIP)) {
sbus_writeb(RES_H_IUS, &channel->control);
ZSDELAY();
ZS_WSYNC(channel);
if (r3 & CHARxIP)
tty = sunzilog_receive_chars(up, channel, regs);
if (r3 & CHAEXT)
sunzilog_status_handle(up, channel, regs);
if (r3 & CHATxIP)
sunzilog_transmit_chars(up, channel);
}
spin_unlock(&up->port.lock);
if (tty)
tty_flip_buffer_push(tty);
/* Channel B */
up = up->next;
channel = ZILOG_CHANNEL_FROM_PORT(&up->port);
spin_lock(&up->port.lock);
tty = NULL;
if (r3 & (CHBEXT | CHBTxIP | CHBRxIP)) {
sbus_writeb(RES_H_IUS, &channel->control);
ZSDELAY();
ZS_WSYNC(channel);
if (r3 & CHBRxIP)
tty = sunzilog_receive_chars(up, channel, regs);
if (r3 & CHBEXT)
sunzilog_status_handle(up, channel, regs);
if (r3 & CHBTxIP)
sunzilog_transmit_chars(up, channel);
}
spin_unlock(&up->port.lock);
if (tty)
tty_flip_buffer_push(tty);
up = up->next;
}
return IRQ_HANDLED;
}
/* A convenient way to quickly get R0 status. The caller must _not_ hold the
* port lock, it is acquired here.
*/
static __inline__ unsigned char sunzilog_read_channel_status(struct uart_port *port)
{
struct zilog_channel __iomem *channel;
unsigned char status;
channel = ZILOG_CHANNEL_FROM_PORT(port);
status = sbus_readb(&channel->control);
ZSDELAY();
return status;
}
/* The port lock is not held. */
static unsigned int sunzilog_tx_empty(struct uart_port *port)
{
unsigned long flags;
unsigned char status;
unsigned int ret;
spin_lock_irqsave(&port->lock, flags);
status = sunzilog_read_channel_status(port);
spin_unlock_irqrestore(&port->lock, flags);
if (status & Tx_BUF_EMP)
ret = TIOCSER_TEMT;
else
ret = 0;
return ret;
}
/* The port lock is held and interrupts are disabled. */
static unsigned int sunzilog_get_mctrl(struct uart_port *port)
{
unsigned char status;
unsigned int ret;
status = sunzilog_read_channel_status(port);
ret = 0;
if (status & DCD)
ret |= TIOCM_CAR;
if (status & SYNC)
ret |= TIOCM_DSR;
if (status & CTS)
ret |= TIOCM_CTS;
return ret;
}
/* The port lock is held and interrupts are disabled. */
static void sunzilog_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
struct uart_sunzilog_port *up = (struct uart_sunzilog_port *) port;
struct zilog_channel __iomem *channel = ZILOG_CHANNEL_FROM_PORT(port);
unsigned char set_bits, clear_bits;
set_bits = clear_bits = 0;
if (mctrl & TIOCM_RTS)
set_bits |= RTS;
else
clear_bits |= RTS;
if (mctrl & TIOCM_DTR)
set_bits |= DTR;
else
clear_bits |= DTR;
/* NOTE: Not subject to 'transmitter active' rule. */
up->curregs[R5] |= set_bits;
up->curregs[R5] &= ~clear_bits;
write_zsreg(channel, R5, up->curregs[R5]);
}
/* The port lock is held and interrupts are disabled. */
static void sunzilog_stop_tx(struct uart_port *port)
{
struct uart_sunzilog_port *up = (struct uart_sunzilog_port *) port;
up->flags |= SUNZILOG_FLAG_TX_STOPPED;
}
/* The port lock is held and interrupts are disabled. */
static void sunzilog_start_tx(struct uart_port *port)
{
struct uart_sunzilog_port *up = (struct uart_sunzilog_port *) port;
struct zilog_channel __iomem *channel = ZILOG_CHANNEL_FROM_PORT(port);
unsigned char status;
up->flags |= SUNZILOG_FLAG_TX_ACTIVE;
up->flags &= ~SUNZILOG_FLAG_TX_STOPPED;
status = sbus_readb(&channel->control);
ZSDELAY();
/* TX busy? Just wait for the TX done interrupt. */
if (!(status & Tx_BUF_EMP))
return;
/* Send the first character to jump-start the TX done
* IRQ sending engine.
*/
if (port->x_char) {
sbus_writeb(port->x_char, &channel->data);
ZSDELAY();
ZS_WSYNC(channel);
port->icount.tx++;
port->x_char = 0;
} else {
struct circ_buf *xmit = &port->info->xmit;
sbus_writeb(xmit->buf[xmit->tail], &channel->data);
ZSDELAY();
ZS_WSYNC(channel);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
port->icount.tx++;
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&up->port);
}
}
/* The port lock is held. */
static void sunzilog_stop_rx(struct uart_port *port)
{
struct uart_sunzilog_port *up = UART_ZILOG(port);
struct zilog_channel __iomem *channel;
if (ZS_IS_CONS(up))
return;
channel = ZILOG_CHANNEL_FROM_PORT(port);
/* Disable all RX interrupts. */
up->curregs[R1] &= ~RxINT_MASK;
sunzilog_maybe_update_regs(up, channel);
}
/* The port lock is held. */
static void sunzilog_enable_ms(struct uart_port *port)
{
struct uart_sunzilog_port *up = (struct uart_sunzilog_port *) port;
struct zilog_channel __iomem *channel = ZILOG_CHANNEL_FROM_PORT(port);
unsigned char new_reg;
new_reg = up->curregs[R15] | (DCDIE | SYNCIE | CTSIE);
if (new_reg != up->curregs[R15]) {
up->curregs[R15] = new_reg;
/* NOTE: Not subject to 'transmitter active' rule. */
write_zsreg(channel, R15, up->curregs[R15]);
}
}
/* The port lock is not held. */
static void sunzilog_break_ctl(struct uart_port *port, int break_state)
{
struct uart_sunzilog_port *up = (struct uart_sunzilog_port *) port;
struct zilog_channel __iomem *channel = ZILOG_CHANNEL_FROM_PORT(port);
unsigned char set_bits, clear_bits, new_reg;
unsigned long flags;
set_bits = clear_bits = 0;
if (break_state)
set_bits |= SND_BRK;
else
clear_bits |= SND_BRK;
spin_lock_irqsave(&port->lock, flags);
new_reg = (up->curregs[R5] | set_bits) & ~clear_bits;
if (new_reg != up->curregs[R5]) {
up->curregs[R5] = new_reg;
/* NOTE: Not subject to 'transmitter active' rule. */
write_zsreg(channel, R5, up->curregs[R5]);
}
spin_unlock_irqrestore(&port->lock, flags);
}
static void __sunzilog_startup(struct uart_sunzilog_port *up)
{
struct zilog_channel __iomem *channel;
channel = ZILOG_CHANNEL_FROM_PORT(&up->port);
up->prev_status = sbus_readb(&channel->control);
/* Enable receiver and transmitter. */
up->curregs[R3] |= RxENAB;
up->curregs[R5] |= TxENAB;
up->curregs[R1] |= EXT_INT_ENAB | INT_ALL_Rx | TxINT_ENAB;
sunzilog_maybe_update_regs(up, channel);
}
static int sunzilog_startup(struct uart_port *port)
{
struct uart_sunzilog_port *up = UART_ZILOG(port);
unsigned long flags;
if (ZS_IS_CONS(up))
return 0;
spin_lock_irqsave(&port->lock, flags);
__sunzilog_startup(up);
spin_unlock_irqrestore(&port->lock, flags);
return 0;
}
/*
* The test for ZS_IS_CONS is explained by the following e-mail:
*****
* From: Russell King <rmk@arm.linux.org.uk>
* Date: Sun, 8 Dec 2002 10:18:38 +0000
*
* On Sun, Dec 08, 2002 at 02:43:36AM -0500, Pete Zaitcev wrote:
* > I boot my 2.5 boxes using "console=ttyS0,9600" argument,
* > and I noticed that something is not right with reference
* > counting in this case. It seems that when the console
* > is open by kernel initially, this is not accounted
* > as an open, and uart_startup is not called.
*
* That is correct. We are unable to call uart_startup when the serial
* console is initialised because it may need to allocate memory (as
* request_irq does) and the memory allocators may not have been
* initialised.
*
* 1. initialise the port into a state where it can send characters in the
* console write method.
*
* 2. don't do the actual hardware shutdown in your shutdown() method (but
* do the normal software shutdown - ie, free irqs etc)
*****
*/
static void sunzilog_shutdown(struct uart_port *port)
{
struct uart_sunzilog_port *up = UART_ZILOG(port);
struct zilog_channel __iomem *channel;
unsigned long flags;
if (ZS_IS_CONS(up))
return;
spin_lock_irqsave(&port->lock, flags);
channel = ZILOG_CHANNEL_FROM_PORT(port);
/* Disable receiver and transmitter. */
up->curregs[R3] &= ~RxENAB;
up->curregs[R5] &= ~TxENAB;
/* Disable all interrupts and BRK assertion. */
up->curregs[R1] &= ~(EXT_INT_ENAB | TxINT_ENAB | RxINT_MASK);
up->curregs[R5] &= ~SND_BRK;
sunzilog_maybe_update_regs(up, channel);
spin_unlock_irqrestore(&port->lock, flags);
}
/* Shared by TTY driver and serial console setup. The port lock is held
* and local interrupts are disabled.
*/
static void
sunzilog_convert_to_zs(struct uart_sunzilog_port *up, unsigned int cflag,
unsigned int iflag, int brg)
{
up->curregs[R10] = NRZ;
up->curregs[R11] = TCBR | RCBR;
/* Program BAUD and clock source. */
up->curregs[R4] &= ~XCLK_MASK;
up->curregs[R4] |= X16CLK;
up->curregs[R12] = brg & 0xff;
up->curregs[R13] = (brg >> 8) & 0xff;
up->curregs[R14] = BRSRC | BRENAB;
/* Character size, stop bits, and parity. */
up->curregs[3] &= ~RxN_MASK;
up->curregs[5] &= ~TxN_MASK;
switch (cflag & CSIZE) {
case CS5:
up->curregs[3] |= Rx5;
up->curregs[5] |= Tx5;
up->parity_mask = 0x1f;
break;
case CS6:
up->curregs[3] |= Rx6;
up->curregs[5] |= Tx6;
up->parity_mask = 0x3f;
break;
case CS7:
up->curregs[3] |= Rx7;
up->curregs[5] |= Tx7;
up->parity_mask = 0x7f;
break;
case CS8:
default:
up->curregs[3] |= Rx8;
up->curregs[5] |= Tx8;
up->parity_mask = 0xff;
break;
};
up->curregs[4] &= ~0x0c;
if (cflag & CSTOPB)
up->curregs[4] |= SB2;
else
up->curregs[4] |= SB1;
if (cflag & PARENB)
up->curregs[4] |= PAR_ENAB;
else
up->curregs[4] &= ~PAR_ENAB;
if (!(cflag & PARODD))
up->curregs[4] |= PAR_EVEN;
else
up->curregs[4] &= ~PAR_EVEN;
up->port.read_status_mask = Rx_OVR;
if (iflag & INPCK)
up->port.read_status_mask |= CRC_ERR | PAR_ERR;
if (iflag & (BRKINT | PARMRK))
up->port.read_status_mask |= BRK_ABRT;
up->port.ignore_status_mask = 0;
if (iflag & IGNPAR)
up->port.ignore_status_mask |= CRC_ERR | PAR_ERR;
if (iflag & IGNBRK) {
up->port.ignore_status_mask |= BRK_ABRT;
if (iflag & IGNPAR)
up->port.ignore_status_mask |= Rx_OVR;
}
if ((cflag & CREAD) == 0)
up->port.ignore_status_mask = 0xff;
}
/* The port lock is not held. */
static void
sunzilog_set_termios(struct uart_port *port, struct termios *termios,
struct termios *old)
{
struct uart_sunzilog_port *up = (struct uart_sunzilog_port *) port;
unsigned long flags;
int baud, brg;
baud = uart_get_baud_rate(port, termios, old, 1200, 76800);
spin_lock_irqsave(&up->port.lock, flags);
brg = BPS_TO_BRG(baud, ZS_CLOCK / ZS_CLOCK_DIVISOR);
sunzilog_convert_to_zs(up, termios->c_cflag, termios->c_iflag, brg);
if (UART_ENABLE_MS(&up->port, termios->c_cflag))
up->flags |= SUNZILOG_FLAG_MODEM_STATUS;
else
up->flags &= ~SUNZILOG_FLAG_MODEM_STATUS;
up->cflag = termios->c_cflag;
sunzilog_maybe_update_regs(up, ZILOG_CHANNEL_FROM_PORT(port));
uart_update_timeout(port, termios->c_cflag, baud);
spin_unlock_irqrestore(&up->port.lock, flags);
}
static const char *sunzilog_type(struct uart_port *port)
{
return "SunZilog";
}
/* We do not request/release mappings of the registers here, this
* happens at early serial probe time.
*/
static void sunzilog_release_port(struct uart_port *port)
{
}
static int sunzilog_request_port(struct uart_port *port)
{
return 0;
}
/* These do not need to do anything interesting either. */